Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Question on angular momentum changes of + or - 2

  1. Feb 7, 2004 #1
    Guess I should know this but...

    Maybe a good quantum guy can help me out.

    In atomic transitions involving orbital angular momentum, L, (or total angular momentum J) , how is a change of + or - 2 accounted for??
    Usually it is said that electromagnetic transitions are forbidden (presumably because they must change by + or - 1); therefore in a 0 to + 2 transition what happens to the excess (loss or gain) in angular momentum ?? How is it accounted for if not radiated electromagnetically?

  2. jcsd
  3. Feb 7, 2004 #2
    I'm interested in what happens too. Photons can only have +-1 definite angular momentum, so I think if the atom doesn't have +-1 momentum along the z-axis, then it can't emit a photon along that axis. So I guess for a total angular momentum quantum number of 2 and component of angular momentum along the z-axis of 2, you'd have to use the rotation matrices and find a direction where there's some amplitude to be in m=+-1, and the photon will be emitted in one of those directions.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook